Johnny Ray

My daughter's 1992 3.1L automatic Firebird started idling erratically a few days ago.


It sometimes displays the "Service Engine" light but shows no codes.

In the driveway the engine idles and responds well. I noticed tonight when the power brakes are applied quickly is when the engine wants to die and then struggles to regain correct idle RPM. The engine dies on occasion. I visually checked all vacuum lines for a leak. I found no obvious suspect line. Is it possible that the power booster could be leaking internally?

Any suggestions will be appreciated guys!

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1992 Artic White Firebird

1997 Black Firebird

CaliCamaroRS

have you guys noticed that the only thirdgens with idle/stall problems are 90-92 V6's???? and, what a coincidence,only 90-92 V6's have a digital EGR valve.


well, you said any suggestions....so my suggestion is carbon build-up on the digital EGR. when you say it dies....does it die on deceleration and when you slow rather quick?????

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Dan
1990 3.1L RS
80 Series Flowmaster
It's fast(er than a 3 cyl metro)

Johnny Ray

The engine has died when she pulls up to a stoplight with the brakes on.

When I was in the driveway tinkering with it, I could put it in Drive and hit the brake hard and it would want to die or struggle to regain correct idle RPM.

In Park I would rev the engine up to 3,000 RPM and it would come down to idle with no problem.

Sound like a digital EGR valve?

Thanks!



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1992 Artic White Firebird

1997 Black Firebird

CaliCamaroRS

hmmm, well that could be some sort of vacuum prob but wouldn't it idle erratically all the time??. how does it not show codes when the SES light comes on? did you check them while the light was on?



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Dan
1990 3.1L RS
80 Series Flowmaster
It's fast(er than a 3 cyl metro)

FAST RS

I had the san problemthe hose from the powerbooset i think its called the thing were the brake fluid is and then the hose runs to the intakle manafold was leaking i noticed mine was swollen replace that and it should be ok. also WERE THE HELL you been i haven seen u on here in ages

Johnny Ray

Hey Fast RS! How ya been doing dude?

I have been playing with my '69 Falcon all winter and have it ready to roll for this summer.

Both of the Firebirds have been running great until this little glitch!

Today I pulled a Service Code #23, #44 and a #45.
#23=Manifold Air Temperature
#44=Lean Exhaust Mixture
#45=Rich Exhaust Mixture

I disconnected the battery for 10 minutes and now no codes are showing up.

Yesterday the engine light wouldn't come on until the engine reached operating temperature.

Idle still drops to 600RPM when I apply the brakes to a full stop and recovers to 900-1000RPM rather quickly.

I ran her car around town for about a hour today and the engine light never did come on.

One question keeps coming to my mind
is how was I pulling a #44 and a #45 at the same time? How could I have a lean and a rich mixture code?





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1992 Artic White Firebird

1997 Black Firebird

FAST RS

Check tht hose iw as tellin you about also maybe your ECM fried it self . When mine went it kept my TC in lock up every were i went killed the trann and it was flloding the engine

TomP

What's up, JR? Looks like that code 23 was stored a while ago, eh? Sometimes the oxy sensor wire gets too close to the exhaust, melts, and grounds out on the pipe. That will make the car run - uh, rich, I think. (I forget, it's been a while.) The computer sees a "0" resistance and sets an error code. But... you're not getting error codes now.

The oxy sensor starts reporting to the computer when the exhaust gets warm enough.. maybe that's a link? Same w/EGR, it won't kick on until the engine's warm (and at high speed & low rpm = cruising down the highway).

How's other stuff? Like the distributor cap/rotor, wires, fuel filter, air filter? Is there a spark plug that's gooped up (been misfiring)?

How's the vac line to the MAP sensor? Yeah, vacuum-testing that booster is probably a good idea.

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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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